Original article
Clinical endoscopy
Likelihood of missed and recurrent adenomas in the proximal versus the distal colon

Presented in abstract form as an oral presentation at the Digestive Diseases Week, June 1, 2009, Chicago, Illinois (Gastrointest Endosc 2009;69:AB108).
https://doi.org/10.1016/j.gie.2011.02.023Get rights and content

Background

Colonoscopy may be less efficacious in reducing colorectal cancer mortality in the proximal compared with the distal colon. A greater likelihood for missed and recurrent adenomas in the proximal colon may contribute to this phenomenon.

Objective

To examine whether a proximal adenoma is associated with the risk and location of missed and recurrent adenomas.

Design

Prospective.

Setting

Polyp Prevention Trial.

Participants

A total of 1864 patients with an adenoma at baseline underwent a follow-up colonoscopy 4 years later (adenoma recurrence). Of these, 1731 underwent a clearing colonoscopy 1 year after the baseline examination (missed adenoma).

Main Outcome Measurements

Association of baseline adenoma location with the risk and location of adenomas found at colonoscopy performed 1 year and 4 years later.

Results

At the year 1 colonoscopy, 598 patients (34.6%) had an adenoma (missed adenoma). Compared with those with a distal-only adenoma at baseline, patients with a proximal-only adenoma at baseline were more likely to have any missed adenomas (relative risk [RR] 1.28; 95% CI, 1.09-1.49) and a proximal-only missed adenoma (RR 2.05; 95% CI, 1.49-2.80). At the year 4 colonoscopy, 733 patients (39.3%) had adenoma recurrence. Patients with a baseline proximal-only adenoma were more likely to have any adenoma recurrence (RR 1.14; 95% CI, 1.00-1.31) and a proximal-only adenoma recurrence (RR 1.52; 95% CI, 1.15-2.02). Sensitivity analyses involving missed adenomas did not materially affect the risk or location of recurrent adenomas at year 4 colonoscopy.

Limitation

Lesions may still be missed on repeated colonoscopies.

Conclusions

Missed and recurrent adenomas are more likely to be in the proximal colon.

Section snippets

Study population

The rationale, design, and results of the PPT were published previously.18, 19, 20 In brief, the PPT was a 4-year multicenter, randomized, controlled trial to assess the effect of a low-fat, high-fiber, fruit and vegetable diet on the risk of colorectal adenoma recurrence. A total of 2079 participants who were at least 35 years old and had 1 or more histologically confirmed adenomatous polyps removed within 6 months from a complete colonoscopy were randomized. Exclusion criteria included

Baseline characteristics

Table 1 shows selected baseline characteristics of study participants by the location of the baseline adenoma. At baseline, 1030 participants (55.3%) had a distal-only adenoma, 503 (27%) had a proximal-only adenoma, and 331 (17.8%) had a synchronous proximal and distal adenoma. A total of 750 patients (37.8%) had an advanced adenoma at baseline: 440 participants (62.4%) had a distal-only advanced adenoma, 111 (15.7%) had a proximal-only advanced adenoma, and 154 (21.8%) had a synchronous

Discussion

We evaluated the association between adenoma location at baseline with the risk of adenoma recurrence and the location of the recurrent adenoma in an attempt to assess differences in susceptibility to adenoma recurrence by location. Our study suggests 3 potential mechanisms underlying a lower protective effect of colonoscopy in the proximal colon. First, we report that missed lesions are more common in the proximal colon. Second, recurrent adenomas and advanced adenomas are more likely to be in

References (34)

  • M.E. Martínez et al.

    Adenoma characteristics as risk factors for recurrence of advanced adenomas

    Gastroenterology

    (2001)
  • E.T. Jacobs et al.

    Association between body size and colorectal adenoma recurrence

    Clin Gastroenterol Hepatol

    (2007)
  • N. Segnan et al.

    Baseline findings of the Italian multicenter randomized controlled trial of “once-only sigmoidoscopy” - SCORE

    J Natl Cancer Inst

    (2002)
  • G. Gondal et al.

    The Norwegian Colorectal Cancer Prevention (NORCCAP) screening study: baseline findings and implementations for clinical work-up in age groups 50-64 years

    Scand J Gastroenterol

    (2003)
  • P.A. Newcomb et al.

    Screening sigmoidoscopy and colorectal cancer mortality

    J Natl Cancer Inst

    (1992)
  • J.V. Selby et al.

    A case-control study of screening sigmoidoscopy and mortality from colorectal cancer

    N Engl J Med

    (1992)
  • S. Subramanian et al.

    Use of colonoscopy for colorectal cancer screening: evidence from the 2000 National Health Interview Survey

    Cancer Epidemiol Biomarkers Prev

    (2005)
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    DISCLOSURE: The following authors disclosed financial relationships relevant to this publication: Dr. Laiyemo is supported by the National Cancer Institute's new faculty recruitment supplement to the Comprehensive Minority Institution/Cancer Center Partnership between Howard University Cancer Center and Sidney Kimmel Comprehensive Cancer Center of Johns Hopkins University (5U54CA091431-09 S1). Dr. Doubeni is supported by a mentored career development award (5K01CA127118-03) from the National Cancer Institute. This research was funded by the Intramural Research Program of the National Cancer Institute, National Institutes of Health. The other authors disclosed no financial relationships relevant to this publication.

    If you would like to chat with an author of this article, you may contact Dr. Laiyemo at [email protected].

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